Your welcome. Just be aware that, even though they can become a part of the Force, if the host they are inhabiting dies they can die too, so it's not a ticket to immortality in battle. But it would explain how you've existed since the time of Darth Bane.
Arcturus mentioned listing a race. I found one for you that matches what you're going for, mostly. http://starwars.wikia.com/wiki/Space_wraith
Other than that, check out the Anzat.
Oh, also, sometimes the Sith leadership might take a while to get back to you on your acceptance. It took them a week to accept me. Have no fear, though! As long as people do not complain about your character being overpowered in your character thread, or find other faults, then the leadership is very unlikely to deny you and you can operate as if you've been accepted. That, or just PM Sreeya: http://www.thestarwarsrp.com/forum/member.php?2852-Sreeya She's capable of accepting people as well.
Well, you have to start off as an Acolyte, but you don't need formal training afaik. You can learn skills and Force abilities via roleplaying with others, and its recommended you RP with others of course, so you can get interest for RP threads by starting an interest check thread in an OOC area.
Hallo there! While I am glad that you showed interest in Xanthus's lesson, it does not seem that you have an actual character signed up. You have to create a character before you can roleplay on Star Wars RP. I'd be glad to help you if you have any questions. ^^